/*
 moxl - Modular XML Library
 Copyright (c) 2007, Malcolm Sparks

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package moxl.tokenizer;

import java.io.IOException;

import moxl.reader.LocateableReader;
import moxl.reader.Location;

public class Tokenizer
{
	private final LocateableReader reader;
	private final TokenizerStateMachine stateMachine;

	public Tokenizer(LocateableReader reader, AbstractTokenizerState startState)
	{
		this.reader = reader;
		this.stateMachine = new TokenizerStateMachine(startState);
	}

	/**
	 * @return the next token, or null if no more tokens.
	 * @throws ParserException
	 */
	public Token nextToken() throws TokenizerException
	{
		try
		{
			return stateMachine.readToken(reader);
		}
		catch (IOException e)
		{
			throw new TokenizerException("Failed to read next token", e);
		}
	}

	public int peekNextCharacter() throws TokenizerException
	{
		try
		{
			reader.mark(1);
		}
		catch (IOException e)
		{
			throw new TokenizerException("Failed to mark position in reader (type of reader is " + reader.getClass().getName() + ")", e);
		}
		int nextChar;
		try
		{
			nextChar = reader.read();
		}
		catch (IOException e)
		{
			throw new TokenizerException("Failed to read next character from reader (type of reader is " + reader.getClass().getName() + ")", e);
		}
		try
		{
			reader.reset();
		}
		catch (IOException e)
		{
			throw new TokenizerException("Failed to reset reader", e);
		}
		return nextChar;
	}

	public Location getPosition()
	{
		return reader.getLocation();
	}

	public void setMode(AbstractTokenizerState mode)
	{
		stateMachine.setStartState(mode);
	}

	public TokenizerStateMachine getStateMachine()
	{
		return stateMachine;
	}

}
